There is a technology for installing a driver in an information terminal such as a personal computer and remotely controlling a printer or a scanner through the driver. According to this technology, it is possible to use the information terminal to remotely use the function of the printer or the scanner. Meanwhile, there is known a technology for attaching an external memory to a printer or a scanner, and performing control such that the printer prints image data stored in the external memory or image data generated by the scanner is stored in the external memory. According to this technology, a user can use the printer or the scanner, without installing a driver in an information terminal.